Automatic voltage-regulating circuit



Jan. 27, 1931'. F. w. scHRAMM AUTOMATIC VOLTAGE REGULATING CIRCUIT Filed Aug. 25, 1928 Counter M Cells INVENTOR BY E Wchmmm/ ATTORNEY until the armature of the voltmeter relay has had time to move ofi of the low contact in case the bus-bar voltage is restored within the specified limits by the operation of relay C1. Were it not for this arrangement relays B2 and C2 would operate and short circuit cell 7 as is explained below, as soon as Bl operated, thus increasing the bus-bar voltage by too great an amount.

With relays Bl and C1 lockedto ground at 211 and with relay A1 released, assume that the bus-bar voltage again falls. The armature o1u relay 1 will again be operated against the low contact reoperating relay 8. The operation of relay 3 will connect battery A to the windings of the A relays. lRelay A2, however, will not operate due t-o the tact that its operating circuit is open at the right back contact of relay B2, which latterV is operated. Relay A2,how ever, operates on thecircuit from battery 4l through the winding of A2 to groundV at 25 through the right back contact of relay B2. The operation of relay 3 also connects ground over lead 19, through the left front contact of relay B1, back contact of relay A2, and over lead 2O to the windings of relays B2 and C2, in parallel, the other side of the windings being connected to battery 15 through the back contact of relay D2. f

Relays B2 and C2 operate over this circuit.V

The operation of relay C2 replaces cell 7 with short circuiting path 26, thus increasing the bus-bar voltage. The operation of relay B2 disconnects the ground obtained over lead 2O from the windings of B2 `and C2 at the lei't back contact of B2 and connects lead 20 to the armature of relay A2 through the left inner front contact of relay B2. The operation of relay B2 also disconnectsground 25 from the winding of relay A2, and reconnects ground 25 to the windings of B2 and C2 through the right front contact of B2, thus holding these relays operated. Relay A2 serves the same purpose as A1 and upon disconnection of ground 25 therefrom due to the operation of relay B2, relay A2 remains operated suiiiciently long to permit the armature of relay 1 to move off the low stud, assuming the voltage now restored tothe proper value, thus preventing the ground on lead 2O Jtrom being connected to the windings of relays B3 and C2 over lead 21. V But for this slow release feature relays B2 and C3 would operate immediately and by shunting out cell 8 would cause too great an increase of the bus-bar voltage.

Upon al further decrease in bus-bar voltage relay 1 again operates against the low stud connecting battery 11 to the A relays. Relays Al and A2 are not affected since their operating circuits are open at the corresponding B relays which are locked up. Relay A3 operates to ground at 26. The operation of relay 1 also causes ground to be applied to lead 19. The ground on lead 19 is applied through the left operated contacts of relay B1 and back contact of A1 to lead 20, and in turn through the left front contact of B2 and back contact of A2 to lead 21 and through the left inner back contact of relay B3 to the windings of relays B2, and C2 in parallel. Battery 15 is applied to the other side of these windings through the back contact of relay D3, causing B3 and C3 to operate. Thus cell 8 is short circuited and lead 21 connected through to lead 22 after release of relay A2,.

The further operation of relay 1 against he low stud connects the ground at battery l over leads 19, 20, 21 and 22 to the B2 and C2 relays, causing their operation 0n battery 15 supplied through the back cont-act of relay D2. Relays B.1 and Clare locked to ground at 27, while the operation of relay C, connects booster cell 9 in series with battery 10. Bat tery 9 is normally connected across the busbars in like polarity with battery 10, as will be seen-.by tracing the circuit trom point 19 through resistance 13 and right back contact ot relay C2, through cell 9 from minus to plus, through the left outer back Contact of C2 and resistance 11 to the other side of the line. The circuit Ytor batterylO is traced from point 19, through the lett inner bach contact Vof relay C2, through battery 10 from minus to plus to the other side of the line. Resistance llis a trickle charging resistance which peri mits battery 10 to slowly charge up battery 9 while relay (his released. Resistances 12 and 13 are inserted in the contact leads of relay C2 to prevent a dead short circuit being connected momentarily across cell 9 during the switching operation which occurs when relay C2. operates.

Returning now to the voltage regulation, when relay C., operates as explained above, a circuit i` traced. from point 19 through the right front contacts ot C4, through battery 9 troni' minus to plus, through the lett front contact of C2, through battery 10 'from minus to plus to the other side of the line. Thus battery 9 is c nnected in series with 10 and the bus-bar Voltage correspondingly increased, causing the arninurey of relay 1 to return to neutral, assuming the proper busbar voltage to be attained. rlhis constitutes the last voltage increase adiustinent. lf the bus-bar voltage again falls, causing relay l to operateagainst the low stud, no further change will occur.

Assume 'on tile other now l causing 1 to nia-lie wt hand that the volt-- through t ie contacts of relay 1. The operation of relay 2 connects battery A to the windings oi the D relays through the iront con tact of relay 2. Relays D2 to B2, inclusive. however, are not operated due to the Jfact that 'for each sach relay, the operating circuit is traced from the winding of the relay in question, through the left back contact of the cuited. With such a scheme an increase inV potential, the regulation coul-d be obtained by Llocating a plurality of resistances in the 'field circuit thereof and varying the voltage by successivelv short circuiting and restoring the same.

What is claimed is: l. Automatic voltage regulating means comprising in combination, a source of potential having associated therewith a plurality of counter lll. M. F. cells for adjusting the terminal voltage by fixed steps, a voltmeter relay associated with said potential source for maintaining the ter ninal voltage within predetermined limits through operation of the armature thereof against one stud when the lower limit is exceeded and against a second stud when the upper limitv is exceeded, switching means individual to said counter E. M. F. cells operative while the armature is in contact with either stud to vary the terminal voltage in, successive steps in a direction to restore said Voltage within said predetermined limits.

Automatic voltage regulating means comprising in combination, a source of potential having associated therewith a plurality of counter E. M. F. cells for adjusting the terminal voltage by lined steps, a voltmeter relay associated with said potential source for maintaining the terminal voltage within predetermined limits through operation ot the armature thereof against one stud when the lower li nit is exceeded and against a second stud when the vupper limit is exceeded, switching means individual to said counter E. M. ll. cells operative while the armature is in contact with either stud to varythe terminal voltage in successive steps in a direction to restore said voltage within said predetermined limits, slow acting means associated with said switching means ior introducing a time interval between said successive voltage adjustments to permit restoration of said voltmetcr relay armature to the neutral position upon readjustment of the terminal voltage within said predetermined limits.

3. Automatic voltage regulating means comprising` in combination, a source of potential having associated therewith a pluralityv of counter E. M. F. cells tor varying the V1terminal voltage in equal steps, a voltmeter relay associated with said potential source for maintaining the terminal voltage within narrow predetermined limits through operation ofthe armature of said relay against one stud when the lower limit is exceeded and against a second stud when the upper limit is exceeded, relay means individual to said cells opera-- tive while said armature is in Contact with either stud to vary the terminal voltage in a. direction to restore said voltage within said predetermined limits, operating circuits for the relay means associated with a given cell being traced through the contacts of the relay means associated with other cells to insure a sequential operation of the relay means associated with successive elements for Varying the terminal voltage in successive steps, slow acting means associated with said relay means Jfor introducing an appreciable time interval between the successive voltage adjustments to permit restoration of said armaturerto the neutral position upon adjustment of the terminal voltage within said predetermined limits.

4. Automatic voltage regulating means comprising in combination, in series across a pair of output terminals, a source of potential and a. -plurality ot counter E. M. F. cells, voltmeter relay connected across said terminals having the armature adjusted to the neutral position for the resultant terminal voltage, and adapted to make contact with one stud for a voltage decrease approximating or exceeding in magnitude that of a counter E. lifA cell, and adapted to make contact with the other stud 'for an increase of like magnitude, means associated with said irst stud operative upon contact of the armature therewith for successively replacing said counter E. M. F. cells with short circuiting paths Vuntil the initial terminal voltage is restored,

means associated with said second stud operative upon contact of the armature therewith to successively reconnect said replaced counter E. M. F. cells until the initial terminal voltage is restored, said means associated with the studs being further operative upon subsequent contact of the armature with either stud to again adjust the terminal voltage by a like process to its initial value and to continue this process indefinitely for successive voltage fluctuations within the limits of adjustment set by the number and magnitude oii the voltage reducing elements.

5. Automatic voltage regulating means comprising in combination, in series between a pair of terminals, a source of potential and a plurality of counter E. M. F. cells for adjusting the terminal voltage in equal steps, a voltmeter relay connected between said terminals adapted to maintain the terminal voltage between predetermined limits by operating the armature thereof against one stud while said terminal voltage exceeds one limit and against the second stud while the other limit is exceeded, means individual to said cells operative while said armature makes Contact with one stud to successively replace said cells with short circuiting paths and while said armature makes contact with the Cfi ice

other stud to successively reconnect said replaced cells. l

6. Automatic voltage regulating means comprising in combination, in series between ,a pair. of output terminals, a source of potential and a plurality of similar counter E. M. F.

cells for varying the terminal voltage, a voltmeter relay connected between said terminals and adjusted to maintain the terminal voltage between predetermined narrow limits through operation of the armature against one stud when the lower limit is exceeded and against a second stud whenthe upper limit is exceeded, relay .means individual to said counter E. M. F. cells operative while said armature makes contact with said first mentionedV stud to successively replace said cells with short circuiting paths, said relay meansv being further operative while said armature makes contact with said last mentioned stud to successivelyv remove said short circuiting paths and reconnect said cells, slow acting means associated with saidrelay means for introducing a time intervall between successive voltage adjustments to permit return of said armature to the neutral'position upon restoration of said terminal voltage within said predetermined limits.

7. Automatic voltage regulating means comprising in combination, in series between a pairv of terminals, a source of potential and a plurality of similar counter E. M. F. cells, a voltmeter relay connected between said terminals for maintaining the voltage between narrow' predetermined limits throughl operation of thearmature aga-instY one stud when the lower limit is exceeded and against a second stud when the upper limit is exceeded, relay means individual to said cells operative while said armature makes contact with the first stud to successively short circuit said cells and operative while said armature makes contact with the second stud to successively remove said short circuits, slow acting means associated with said relayA means to introduce an appreciable time interval between voltage adjustmentsy to permit `return of said arma` source for maintaining the terminal voltagek Within predetermined limits through operation of the armature thereof against one stud when the lower limit is exceeded and against a second stud when the upper limit is exceeded, [switching means individualto said adjusting elements operative while the armature is in contact with either stud to vary the terminal voltage in successive steps in a adjusting elements for controlling *volta-ge' changes in one direction and asecond such chain of relays for controlling voltage changes in the opposite direction.

9. Automatic voltage regulating means comprising in combination, a source of po-y tential having associated therewith a plurality of adjusting elements for adjusting the terminal voltage by fixed steps, a voltmeter relay associated with said potential source for maintaining the terminal voltage within predetermined limits through operation of the armature thereof against one study when the lower limit is exceeded and against a second stud when the upper limit is exceeded, switching means individual to said adjusting elements operative while the armature is in contact with either stud to vary the terminal voltage in successive steps in adirection to restore said voltage within said kpredetermined limits, said switching means including a chain of relays individual to said adjusting elements for controlling voltage changes in one direction and a second such chain of relays for controlling voltage changes in the opposite direction, slow acting means associated with said switching `means for introducing a time interval ybetweensaid successive voltage adjustments to permit restoration of said voltm'eterV relay armature to the neutral position upon readjustment of the terminal voltage Within said predeter-l mined limits.

10. Automatic voltage regulating means comprising in combination, a source of potential. having associated therewith a plurality of adjusting elements for varying the terminal voltage 1n equal steps, a 'voltmeter relay associated with said potential source for maintaining'the terminalvoltage within narrow predetermined limits through operation of the armature of said relay against one stud when the lower limit is' exceeded and against a second stud when the upper limit is exceeded, relaymeans individual to said adjusting .elements operative while said armature is in contact with either stud to vary the terminaluvoltage in a direction to restore said voltage within said predetermined limits, said relaymeansincluding a first chain of relays individual tosaid adjusting elements for controlling voltage changes in one direction', and a'second such chain ofk relays for controlling voltage changes in the opposite direction, operating circuits for the relay means associated with a givenl adjusting` element being traced through the contacts ofthe relay means associated with other adjusting elements to insure a sequentialoperation of the relay means associated with successive elements for varying the terminal voltage in successive steps,

slow acting means associated with said relay means for introducing an appreciable time interval between the successive voltage adjustments to permit restoration of said armature Vto the neutral position upon adjustment ci' the terminal voltage within said predetermined limits.

ll. Automatic voltage regulating means Y comprising in combination, in series between a pair of output terminals, source ot potentia-l and` plurality of similar resistances, a voltmeter relay connected between said ternilnals loil maintaining the voltage between narrow predeterminedlimits through operation. of the armature thereof against one stud when the lower limit is exceeded and against a second stud when the upper limit is ei;- ceeded, relay means individual to said resistances operative while said armature ina-lies contact yith the lirst stud tosucces sively short-circuit said resistances and other relay means individual to saidresistances operative while said armature makes Contact with the second stud to successively remove said short-circuits, slow-acting means associated with said relay means to introduce an appreciable time interval between voltage adjustments to permit return of said armature to the neutral position upon restoration of the terminal voltage within the said predetermined limits.

12. Auto-matic voltage regulating means comprising in combination, a source or' potential having associated therewith a plurality of voltage reducing elements and a plurality of voltage increasing elements 'for adjusting the terminal voltage by'fixed steps,

' a voltineter rela-y associated with said potential source for maintaining the termina-l voltage within predetermined limits through the operation of the armature thereof against one stud when the lower limit is exceeded and against a second stud when the upper. limit is exceeded, and switching means individual to said voltage increasing and reducing elements and operative'while said armature is in contact with either stud to vary the terminal voltage in successive steps'in a direction to restore said voltage withinV said predetermined limits.

13. Automatic voltage regulating means comprising in combination, a source of potential having associated therewith a plu-rality ot voltage increasing elements and a plurality oic voltage reducing elements for adjusting the terminal vo-ltage by lined steps, a voltmeter relay associated with said potential source or maintaining the terminal voltage within predetermined limits through the operation of the armature thereof against one stud when the lower limit is exceeded and against a second stud when the upper limit is exceeded, switching means individual to said voltage increasing elements operative while said armature isin contact with one ot said studs to increase the terminal voltage Ain successive steps to a voltage within said with the other osaid studs to reduce the terminal voltage in successive steps toa voltage within said predetermined limits. A

il. Automatic voltage regulating means comprising in combination, a source oi' potential having associated therewith a plurality of voltage increasing elements and a plurality or" voltage decreasing elements foradj Listing the terminal voltage by fixed steps, a voltmeter relay associated with said potential source for maintaining terminal voltage within predetermined limits through the operation o the armature thereof against oneV stud when the lower limit is exceeded and against a second stud when the upper limit is exceeded, and switching means operative while said armature is in contact with one of said studs to disassociate in successive steps said voltage reducing elements from said potential source and to associate therewith in successive steps said voltage increasing elements and operative while said-'armature is in contact with the other of said studs Vto disassociate in successive steps said voltage increasing elements trom said potential source and to associate therewith in succes-V sive steps said voltage reducing elements.

l5. Automatic voltage regulating means. comprising in'coinbination, a source of po-V tential havingassociated therewith a plurality ot adjusting elements/tor adjusting the.

terminal voltage by lined steps, a. voltmeter relay associated with said potential source, a plurality of chains ot relays, each chain including a control relay, a switching relay necting said relays in such a manner that when the terminal voltage is being reduced, the control relay and the switching relay ot each chain are controlled by said first slowrelease relay of their own chain, said first slow-release relay of each chain is controlled j oiiitly by said voltmeter relay, the control relay of its own chain and the control relay and said first slow-release relay of the next preceding chain, and said second slow-release relay of each chain is controlled jointly by said voltmeter relay and thecontrol relay of its own chain, and in suoli manner that ywhen the terminal voltage is being increased, the control relay and the switching relay of each chain are controlled jointly by said voltmeter relay, the control'relay and said second slow-release 'relay of Aeach preceding chain` and said rst slow-release relay of their own chain, said Hrst slow-release relay kof each chain is controlled jointly by said Voltl'neter relay, the control relay of its own chain, and said frst sloyvlelease relay and the control relay of the next succeedingr chain, und said second slow-release relay of each Chain is controlled jointly by said voltlneter relay and the control relay of its own chain.

In testimony whereof, I have signed my name to this specification this 23rd day of August, 1928.

FRED W. SCHRAMM. 

